The present invention relates to a semiconductor radiation detector, which allows semiconductor radiation detectors to be arranged in a three-dimensional direction and a radiation imaging apparatus using the same.
A semiconductor radiation detector is provided with a semiconductor device made of CdTe, CdZnTe, etc., and electrodes formed on both sides of this semiconductor device designed to pick up electric charge generated when radiation such as X-rays or γ-rays enter the semiconductor device by applying a bias voltage between these electrodes from the electrodes as a signal.
When a semiconductor radiation detector is used for a medical radiation imaging apparatus, etc., the semiconductor radiation detector is connected on a wiring board to form a radiation detection section (see JP-A-2003-84068 (paragraph 00024, FIG. 3), for example).
A PET (Positron Emission Tomography), which is a kind of a medical radiation imaging apparatus, is intended to improve spatial resolution. However, the device described in JP-A-2003-84068 can detect γ-rays mainly on a plane of incidence of γ-rays (e.g., X-Y plane) by separating their positions but cannot detect γ-rays in the direction of incidence of γ-rays (e.g., Z-direction) by separating the positions. That is, the device cannot detect γ-rays by separating the positions in the three-dimensional direction. Thus, it cannot improve spatial resolution sufficiently.
It is an object of the present invention to provide a semiconductor radiation detector and radiation imaging apparatus capable of improving spatial resolution.